Dental instrument



July 6, 1937. D. E. BOST I DENTAL INSTRUMENT Filed July 18, 1936 mm NW!,Dauz'd E. Bast N N m Nw Patented July 6, 1937 UNETE STATS PATENT()FFICE 6 Claims.

This invention relates to a dental instrument and more particularly butnot necessarily to a wax gun.

It is one object of this invention to provide a 5 dental instrument thatshall be particularly adapted for discharging wax or other patternmaking material into a prepared cavity of a tooth. When the cavityincludes more than one surface of the tooth a fitted matrix around the10 cavity and tooth provides a proper form for the reception of the waxas it is discharged from the gun. It is understood that the patternresulting from. the filling of the prepared cavity with wax is usually astep in the construction of a J metal casting which serves as thefinished filling for the tooth.

Another object is to provide a dental instrument that shall be adaptedto discharge a predetermined amount of wax or other material during oneactuation of the device.

A further object is to provide a dental instrument that shall dischargea pre-determined amount of wax or other material intermittently and atindependent operations of the device.

25 A still further object is to provide a dental instrument having theabove characteristics that shall be novel in construction, rugged,efiicient in operation, particularly adapted for the use for which it isintended and comparatively inexpensive to manufacture.

Theabove and other objects will be made apparent throughout the furtherdescription of the invention when taken in connection with theaccompanying drawing wherein like reference char- 35 acters refer tolike parts. It is to be distinctly understood that the drawing is not adefinition of the invention but merely illustrates one form of thedevice showing a preferred structure for carrying out the invention. Theinvention will be defined by the appended claims.

In the drawing:-

Figure 1 is a side elevational view of a device embodying the invention,

Figure 2 is a sectional view taken along the line 2-2, Figure 3,

Figure 3 is a sectional view taken along the line 2-3, Figure 2 lookingto the left,

Figure 4 is a sectional View taken along the same line as Figure 3 butlooking to the right,

Figure 5 is a fragmental view in section showing a modification of theinvention, and

Figure 6 is a sectional view taken along the line 6-5, Figure 5.

In the forms shown, it indicates a cylinder having its upper endthreaded at it to receive a headmember l2. The head member l2 contains achamber l3 communicating with the interior of the cylinder 10.Projecting from the head I2 is a nipple M preferably formed integrallytherewith and having an opening or passage-way l5 disposed therethroughand communicating with the chamber 13. The lower end of the cylinder [8terminates in a downwardly ext-ending handle and guide portion l6 formedintegrally with the cylinder and having a cross section substantiallysemi-circular in shape. A piston ll is slidably positioned within thecylinder iii and terminates at its lower end in a rearwardly extendingintegrally formed reduced portion or member 58. The outer surface of themember i8 is preferably concave or semi-circular in shape for slidablycontacting the co-operating inner surface of the semi-circular handleportion IS. The handle member It operates to act as a track and guidefor the member I8 which is adapted for relatively slidable movementtherewith. The other or inner surface of the member i8 is provided atits upper portion with a rack l9 having tooth receiving notches 20spaced apart a pre-determined distance.

Novel means is provided for urging the rack forward of the device andprogressively moving the piston l! through the cylinder in steppedrelation as required by the operator. This means comprises a handlemember 2i arcuate in shape to render it easy to be grasped with the handof an operator. The end of the handle member 2| is pivotally mounted bymeans of a pin or shaft 22 extending through the lower side walls of aband or clamping member 23. The clamping member 23 extends around thelower end of the cylinder iii. The end of the member 2| is so positionedwithin the band member 23 as to form a stop for the piston I1 anddefining the pistons extreme innermost portion within the cylinder ill.In order that the rack together with the piston may be moved forwardstep by step, there is provided a pawl member 24 having its lower endturnably mounted adjacent the inner side of the member 2 l. The member2| is provided with a recess 25 adapted to receive a projection or lug26 extending from the lower end of the pawl 24. The lug 26 is bifurcatedlongitudinally for receiving and accommodating a leg 2'! of a springmeans represented in its entirety by 28 later to be described. The lug26 is provided with an opening 29 disposed at substantially right anglesto the bifurcation therein and adapted to receive a pin 3| having itsends extending into the side walls of the recess 25 provided in thehandle member 2| and turnably supporting the lower end of the pawl 24,the latter being cut away at 32 to permit free movement of the lower endof the pawl with respect to the co-operating and adjacent surfaces ofthe member 2|. The upper end of the pawl is provided with a tooth 33 forengaging and co-operating with the notches or grooves provided andforming the rack H3. The upper end of the pawl 24 is biased toward therack l9 by means of a coil spring 34 mounted in oppositely disposedrecesses 35 and 36 formed in adjacent surfaces of the members 2| andpawl 24 respectively.

It can now be readily understood that since the lower end of the pawl 2dis turnably mounted on the member 2! and at a point positioned offcenter and at a distance from the axis 22 of the member 2! that uponmovement of the member 2| towards the co-operating handle portion iiithe pawl will be carried forward sufficiently to move the rack IS adistance equal to the spacing of the notches 2b in the rack I9.Therefore upon each closing movement of the handle 2i the piston will becarried forward in steps and will urge wax or other material through thechamber it in the head portion I I and out through the passageway 85.

For the purpose of biasing the handle member 2i in open position aspring means 28 is provided and consists of a pair of legs 2? and 21'formed in substantially V-shape and connected at the apex of the V bymeans of a loop 3?. The spring means 255 extends through an opening 38formed through the pawl t l, the means 28 being so positioned that theloop 37 will extend into the opening 38 and adapted to receive a pin 39extending through substantially the center of the opening 38 and havingits end anchored into the opposite side walls of the open.- ing 38. Thefree ends of the legs 2? and 21' are adapted to rest on and pressagainst the opposing sides or surfaces of the handle member 2i and therack member Iii respectively. These members 2i and I8 may be provided ontheir inner faces with a groove M for guiding the inner ends of thelegs'Z'l and 2? of the spring means 28.

The head portion H is constructed so as to provide an increasedthickness around the periphery thereof as shown at 42. This increase inmaterial permits the head II to be heated and retain such heats ofsufficient length of time to render the wax therein pliable andworkable. The head II maybe heated by a direct flame or the gun may beconstructed with a builtin resistance coil and heated by electricity asshown in Figures 5 and 6. The resistance coil 43 may be connected withinthe headi I as shown or associated therewith in any manner that willproperly supply heat to the head ii. The resistance coil 53 may beprovided with a pair of contacts Ml and d5 adapted to engage and contactwith similar contacts supplied with a source of electricity.

In the operation of the device the head It is removed from the upper endof the cylinder It and the upper end of the pawl 24% is disengaged fromthe rack 59 by moving it against the spring 34 after which time thepiston ll together with the member 58 and rack I9 is shoved to itslowermost position and until the lower end of the piston ll contacts theupper end or stop member of the handle 2i. The cylinder IE3 is thenfilled with wax or other material to be employed, after which time thedesired type of head II is assembled on the upper end of the cylinder.The device is now in position for actuating the handle ill for carryingthe rack I9 and piston Il forward which will urge the wax through theheated head ll out the opening I5 provided through the nipple I 3.

While there has been illustrated and described only two embodiments ofthe invention, it will be obvious to those skilled in the art thatcertain structural changes may be made in the device as well as othermodifications, substitutions, additions and omissions without departingfrom the spirit and scope of the appended claims.

What I claim is:

1. A dental instrument comprising a cylinder having a rearwardlyextending integrally formed handle member, said handle member beingsubstantially semi-circular in shape, a piston in said cylinder having arearwardly extending rack member integrally formed therewith, means formoving said rack to cause said piston to slide within said cylinder, thesaid semi-circularshaped handle member being adapted to receive saidrack member and serve as a track therefor, the said rack moving meansincludes another handle member having one of its ends turnably mountedadjacent the rear end of said cylinder and adapted to limit the rearwardmovement of said piston in said cylinder.

2. A dental instrument comprising a cylinder, a piston slidable therein,means for urging said piston through said cylinder, means for limitingthe movement of said piston in one direction in said cylinder, the firstsaid means including the second said means, and means for turnablymounting the said last said means adjacent one end of the said cylinder.

3. A dental instrument in accordance with claim 2 wherein the said firstsaid means includes a rack extending from one end of said 'piston andformed integrally therewith, and a pawl carried by the said second saidmeans for engaging and actuating said rack.

i. A dental instrument in accordance with claim 2 wherein the saidcylinder terminates in a rearwardly extending integrally formed handlemember, the said handle member having a cross section substantiallysemi-circular in shape and adapted to receive and guide the first saidmeans during the movement of said piston in said cylinder.

5. A dental instrument comprising a cylinder,

a piston therein having a rearwardly extending integrally formed rackmember, and a pair of handle members, one of said handle membershaving across section substantially semi-circular in shape and formed integrallywith said cylinder, the other one of said handle members is turnablymounted at one of its ends adjacent the rear end of the said cylinderand operates as a stop member for limiting the rearward movement of thepiston through said cylinder.

6. A dental instrument comprising a cylinder, a piston therein havinga'rearwardly'extending integrally formed rack member, and'a pair ofhandle members, one of said handle members having a. cross sectionsubstantially semi-circular in shape and formed integrally with saidcylinder, means is provided for actuating the said rack member forurging the said piston through said cylinder, the said means including apawl member having one of its ends turn-. ably supported on the other ofsaid handle members, and means for biasing the other end of said pawlinto contact relation with the said rack.

DAVID E. BOST.

